Various forms of apparatus are known for supplying heated and humidified air to patient for inhalation therapy. Examples of such apparatus are described in U.S. Pat. No. 2,449,853 to Karp, U.S. Pat. No. 3,526,226 to Stem, and U.S. Pat. No. 4,635,630 to Noir et al.
The prior an apparatuses mentioned hereinabove are generally intended to supply air only for inhalation purposes in response to a breathing-in action by a patient and are not designed to provide a flow of warm humidified air to the nasal mucosa. In none of the prior art apparatus is there a teaching or suggestion that the stream of vapor reaches the nasal mucosa of the patient without requiring inhalation by the patient.
Applicant is aware of U.S. Pat. Nos. 4,369,777 and 4,401,114 to Lwoff et al., in which a stream of heated and humidified air is supplied to the nasal mucosa, but said inventions do not provide humidified air by active participation of the patient in the form of exhalation. Furthermore, the former of the two Lwoff et al. apparatuses is not hand-held, but is instead awkward and cumbersome comprising a heating and combining apparatus located in an outlet member which is remotely connected to the remainder of the apparatus via an air conduit and water conduit. Both Lwoff et al. apparatuses are complex in design and significantly more expensive than the present invention.
Applicant is also aware of the teachings of U.S. Pat. No. 4,523,589 to Krauser which houses a fan or blower and temperature control heating elements to warm the air. Here again, the prior art does not show the user of the device orally providing the air pressure which ultimately forces the air/water vapor mixture into the nasal passages. The Krauser apparatus is also complex in design and expensive relative to the present invention.
Some effort has been directed in the art toward achieving a portable, lightweight and inexpensive gas humidifier as exemplified by U.S. Pat. No. 4,597,917 to Lunsford. However, this device does not provide for repeated or extended therapy as it relies on heat producing chemical substances which, once reacted, are no longer useful. The unit is intended to be disposable and primarily for emergency use only.